A variety of laryngeal masks based on different design principles are known and available on the market. The majority of all the laryngeal mask heads have a cover plate that is positioned dorsally and is connected to a supraglottic tube. A respiration chamber, which is surrounded by a cuff, is present on the ventral side of the laryngeal mask head. In the majority of all known laryngeal mask heads, this cuff is inflatable. Typical examples of such laryngeal masks in which the laryngeal mask head has a cover plate positioned dorsally and a ventral respiration chamber, wherein the respiration chamber is surrounded by an inflatable cuff, are disclosed, for example, in U.S. Pat. No. 5,878,745, US Patent 2003/0037790 and U.S. Pat. No. 7,040,322. Laryngeal masks in which the laryngeal mask head has a non-inflatable cuff are much less common. Such laryngeal masks are usually designed in one piece by forming the laryngeal mask head and the supraglottic tube in one piece having approximately the shape of a handheld showerhead. EP 0 389272 discloses a laryngeal mask, which may also be designed with a non-inflatable cuff, in which case this cuff has a peripheral collar facing the ventral direction to improve the seal. This laryngeal mask or laryngeal mask head is considered to be the most proximate prior art. GB Patent 2,404,863 also discloses a laryngeal mask, wherein the laryngeal mask and the supraglottic tube are connected to one another in one piece here. The adjustment in the shape of this laryngeal mask is also accomplished here, as in the aforementioned EP 389272, by means of a peripheral collar having an integrally molded cuff.
On the other hand, EP 1875937 discloses a type of laryngeal mask similar to that in the aforementioned GB Patent 2,404,863, wherein the seal here is implemented essentially by an improved anatomically adjusted shape. Ultimately reference is also made to EP 1938855, in which a supporting ring is integrally molded on the cuff by means of a thin-walled elastic connection instead of the peripheral collar.
All the laryngeal masks having non-inflatable cuffs described here provide only a certain elastic adjustment, which is performed in the ventral-dorsal direction. None of the aforementioned approaches discloses an adjustability in size and shape using only non-pneumatic means in the lateral-medial and/or ventral-dorsal directions.